Delay element for fuses



-1 1945 R. 1.. GRAUMANN I.-Tl"- AL 38L90 DELAY ELEMENT FOR FUSES I FiledSept/-18, 1933 gases and flame from the Patented Aug. 14, 1945 I RaymondL. Graumann,

Max Fischer, Washington,

Alexandria, Va., and

f Application semester 1s, ieaaseriamo. 689,918 11 Claims. (01. 102-75)I .(Grantedi under .theact of March 3,.1'883, as

, amended This invention relates to a device'for delaying the passage ofthe flame from the percussion ex- 'plosive material of a primer to thedetonator of a fuse-v I Among the objects of this invention are: Toprovide means for causing a predetermina-ble delay, variable withincertain .limits, in the time of passage of flame from the. primer to thedelay pellet and detonator; to separate the detonator from the fusetrain by a septum to produce a more violent irruption of the detonatorgasses into the fuse train; and to provide amoisture proof incl'osurefor the primer which also insures obturation of the gases.

With the above .and other objects in view, the I invention consists inthe construction, combination and arrangement of parts as willbehereinafter morefully described.

.Reference is to be had to the accompanying drawing forming a part ofthis specification in which like reference characters indicatecorrespending parts throughout the several views and in which:

Fig. 1 is a side elevation, mainly in section, of a complete fuse withthe present invention as sembled therein; I

Figs. 2 to 6 are longitudinal sections of various embodiments of theinvention; and I Fig. '7 isa' transverse section on the line 1-'I ofFig. 2. g I

Our invention is adapted for use in fuses in which it is desired tocause a time delay between the explosion of the primer and the firing ofthe booster charge thereby. The several modifications illustrated are,in general, similar, but vary in certain details that produce somewhatdifferent effects.

, Referring particularly to Fig. 2, the delay element comprises a body 8having in it a chamber to receive the baffle member 9 in which is alongitudinal transversely extending bore II, the two forming a passageforflame from the percussion explosive wafer l2 of the primer into thechamber -I3.de fined by a circumferential channel in member 9 .and thewall of body 8. The lower end of the baffle member is seated upon ashoulder l4 formed at the junction of the chamber formember 9 withsmaller chamber I5 in which the delay pellet i6 and the detonator I! areplaced. Slots 18 in baflie .9 place the chamber l3 in communication withthe chamber [5 and permit the passage of former chamberto the latterv toignite delay pellet 16. The volume of chamber 13 may be varied bychanging the depth or the width of the channel in member 9, which willresult in a difference in the pressure of the gases in the delay elementduring the burning of delay pellet .l 6 and .hence'will contro1,-.to acertain extent the rate of burningbf that pellet.

April 30, 1928;..37-0 O. G. 757)- Experiments have shown that thedifference in time so-brought about may be as great as .005 of a second.It is to be understood that the delay introduced by the gas pressureis'in addition to, and not a substitute for, the control of the rate ofburning by compressing the material of the delay pellet.

The percussion wafer 12 is in contact with anvil I 9 that is disposedabove the upper end of flame duct I0 and isinclosed, together with theanvil,

in-a cup 20, preferably ofthin copper. Heretofore the inclosure ofthe-percussion waferhas not been moisture-proof and to overcome thisdefect we have provided a second copper cup 21 disposed over cup tendingflange 22 at its open end. A cap 23 having in it an opening 24 for thepassage of the firing pin is in screw-threaded engagement with body 8and has formed in it a shoulder 25 that clamps flange 22 tightly againstthe end, of body 8 and effectively excludes all moisture. The .aperture26 is provided in the lower end of body 8 to permit passage of the flamefrom the detonator to the fuse train. In Fig. 2 a standard type ofprimer is used with the addition of the moisture excluding cup 2|.

The form of delay element'shown m Fig. 3 is very similar to that in Fig.2 but differs therefrom in that the percussion wafer I2 is inclosed inthe moisture excluding cup 2|, but the usual cup 20 has been omitted. 'Afurther difference is that a relatively thick septum-0r Wa1l2'l isinterposed between detonator H ,and aperture 26 to prevent the detonatorgases from passing to the fuse train until a high-pressure has beenbuilt up in body- 8, which pressure, .after .it has bebore 10 thatcommunicates with a come sufliciently great to rupture septum 21, causesa violent outrush of the gases. The sepe tum 21 is a disc which may beof metal of suitable thickness and physical properties or of any othermaterial adapted to the purpose in view, and is retained in placethrough being clamped between the end of body 8 and a cap'28 screwedthereon. In Fig. 4 a'percussion wafer i2, anvil 29 and washers 30 areassembled in cup 2| to form a unit-therewith. Otherwise the constructionis like that of Fig.2.

Fig. 5 shows a combination of the features I of the modificationsdisclosedin Figs. 2 and 3 but instead of clamping a separate elementagainst body 8 to form a restraining septum between detonator I1 andaperture 26 an integral Wall 3! is .leftbetween chamber I5 and aperture26, which serves the same purpose as does disc '21 in Fig. '3.

t The application of the moisture proofing feature of our invention'to asmall arms cartridge case is shown in Fig. 6. The moisture proofing cup2| is clamped between the annular member 3.2.an d the disc 33 seatedonthe bottom of. the

20 and having a laterally exprimer'cavity in cartridge case 34. Aportion35 of the head of the cartridge case is spun over the sloping shoulder36 of annular member 32.

Fig. 1 illustrates the location of the delay ele- I ment when assembledin a fuse, the parts of which are shown in the armed position. As isgeneral practice the stock 37 carries a booster charge 38 that iscontinued upwardly in the fuse train 39. The striker 40 is moveddownward by the inertia of member 4| upon impact of the bomb and drivesfiring pin 42 against the primer, designated generally by 43, whichcauses the explosion of the percussion wafer l2 thereof. The flame fromthe wafer rushes through bores l and ii into chamber 13 and thencethrough slots l8 to delay pellet I which burns-and ignites detonator H,the flame and gases from which are communicated to the powder. train andthence to booster charge 38. For the purpose of concrete illustrationthere has been shown in Fig. 1 a tail fuse for an aerial bomb, therebeing connected to the fuse a shaft 44 that is rotated, during the fallof the bomb, by fins attached thereto (not shown), to move the parts hithe fuse from the unarmed to the armed posi- It will be understood thatthe above description and accompanying drawing comprehend only thegeneral and preferred embodiment of our invention and that variouschanges in construction, proportion and arrangement of parts may be madewithin the scope of the appended claims without sacrificing any of theadvantages of our invention.

This invention may be manufactured and used of any royalty thereon.

We claim:

l. A delay element for fuses, comprising a body having a first chamber,a of less cross-sectional area than ber in communication with said firstchamber, and an aperture extending from an exterior surface of said bodyto the second chamber; a battle member in said first chamber having alongitudinal bore of less length than the member, a transverselyextending passage through the member connecting with said bore, acircumferential channel in the surface of. said member of less widththan the length of the member and grooves extending from one end of saidmember to said channel; a delay pellet in said second chamber adjacentsaid end of said member, detonating material adjacent to said pellet, ananvil disposed at the other end of said member, percussion explosivematerial contacting said anvil, a readily deformable member in whichsaid anvil and said material are disposed, a fianged cup of readilydeformable moisture proof material inclosing said percussion material,said anvil and said deformable member, and a cap engaged with said bodyto clamp the flange of said cup in moisture proof contact with saidbody, said cap being apertured to permit a firing pin to contact thebase of said cup.

2. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than the first chambeer incommunication with said first chamber, and an aperture extending from anexterior surface of said body to the second chamber; a baffle member insaid first chamber having a longitudinal bore of less length than themember, a

the first chamsecond chamber.

QR-of themember and grooves extending from one end of said member tosaid channel; a delay pellet in said second chamber adjacent said end ofsaid member, detonating material adjacent said pellet, a relativelystrong septum between said detonating material and the said aperture insaid body, an anvil disposed at the other end of said member, percussionexplosive material contacting said anvil, a flanged cup of readilydeformable moisture proof material inclosing said percussion materialand said anvil and a cap engaged with saidbody to clamp the flange ofsaid cup in moisture proof contact with said body, said cap beingapertured to permit a firing pin to contact the base of said cup.

3. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than the first chamber incommunication with said first chamber, an aperture extending from anexterior surface of said body to the second chamber; a baffle member insaid first chamber having a longitudinal bore of less length than themember, a transversely extending passage through the member connectingwith said bore, a circumferential channel of less width than the lengthof said member and grooves extending from one end of said member to saidchannel; a delay pellet in said second chamber adjacent said end of saidmember, detonating material adjacent said pellet, a relatively strongseptum between said detonating material and the said aperture in saidbody, an anvil disposed at the other end of said member, percussionexplosive material contacting said anvil, a flanged cup of readilydeformable moisture proof material disposed at the other end of saidmember, a percussion explosive material disposed in the closedend ofsaid cup, washers to retain said material in said cup, and an anvilextending through said washers to contact said percussion material; anda centrally apertured cap in screw threaded engagement with said body toclamp the flange of said'cup against said body. v

4. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than said first chamber incommunication with said first chamber, a closure for one end of saidsecond chamber, a centrally apertured cap in screw thread engagementwith said body to clamp said closure against said body; a bafile memberin said first chamber, said member having in it a longitudinal bore ofless length than the length of said bore, a transverse borecommunicating with said longitudinal bore and a'circumferential channelof les'swidth thanthe length of said channel and grooves extending fromsaid channel to one end of said member; an anvil mounted at the otherend of said member, percussion explosive material disposed in contactwith said anvil, a deformable moisture proof cup of moisture proofmaterial having a flange at its open end disposed around said anvil andsaid material, a centrally apertured cap in screw threaded engagementwith said body to clamp the flange of said cup against said rialdisposed against said closure and a delay pellet interposed between saiddetonating material and said baffle member,

5. A delay element for fuses, comprising a body having a first chamber,a second chamber of less body, detonating mate-' communication with ber,a transverse bore communicating with said longitudinal bore and acircumferential channel of less widththan the length of said member, andgrooves extending from said channel to an end of said member; an anvildisposed at the other end of said member, percussion explosive materialin contact with said anvil, a cup of readily deformable moisture proofmaterial having a flange at its open end disposed around said anvil andsaid material, a centrally apertured cap in screw threaded engagementwith said body to clamp the flange of said cup against said body,detonating material in said second chamber and a delay pellet interposedbetween said detonating material and said member.

6. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than the first chamber insaid first chamber, and an aperture extending from an exterior surfaceof said body to the second chamber; a baffle member in said firstchamber having a longitudinal bore of less length than the member, atransversely extending passage through-the member connecting with saidbore, a circumferential channel of less width than the length of saidmember and grooves extending from one end of said member to saidchannel; an anvil disposed at the other end of said member, percussionexplosive material contacting said anvil, a readily deformable member inwhich said anvil and said material are disposed, a able moisture proofmaterial inclosing said percussion material, said deformable member andsaid anvil and a cap engaged with said body to clamp the flange of saidcup in moisture proof contact with said body, said cap being aperturedto permit a firing pin to contact the base of said cup.

7. A delay element for fuses, comprising a bodyhaving a first chamber, asecond chamber of less cross-sectional area than the first chamber incommunication with said first chamber, an aperture extending from anexterior surface of said body to the second chamber; a baflle member insaid first chamber having a longitudinal bore of less length than themember, a transversely extending passage through the member connectingwith said bore, a circumferential channel of less width than the length,of said member and grooves extending from One end of said member to saidchannel, an anvil disposed at the other end of said member, percussionexplosive material contacting said anvil, a flanged cup of readilydeformable moisture proof materialinclosing said percussion material andsaid anvil and a cap engaged with said body to clamp the flange of saidcup in moisture proof contact with said body, said cap being aperturedto permit a firing pin to contact the base of said cup.

8. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than the first chamber incommunication with said first chamber, an aperture extending from anexterior surface of said body to the second chamber; a baffle member insaid first chamber having a longitudinal bore of less length than themember, a transversely flanged cup of readily deform-.

extending passage through the member connecting with said bore, acircumferential channel of less width than the length of said member andgrooves extending from one end of said mem- 5 ber to said channel; ananvil disposed atthe other end 'of said member, percussion explosivematerial contacting said anvil, a flanged cup of readily deformablemoisture proof material disposed at the other end of said member,percussion explosive material disposed in the closed end of said cup,washers to retain said material in said cup,

and an anvil extending through said washers to contact said percussionmaterial; and a centrally apertured cap in screw threaded engagementwith'said body to clamp the flange of said cup against said body.

9. A delay element for fuses, comprising a body having a first chamber,a second chamber of less cross-sectional area than said first chamber incommunication with said first chamber, a closure for one end of saidsecond chamber, a centrally apertured cap in screw thread engagementwith said body to clamp said closure against said body; a baffle memberin said first chamber, said member having in it a longitudinal bore of'less length than the length of said bore, a transverse borecommunicating with said longitudinal bore and a circumferential'channelof less width than the length of said channel and grooves ex- 80 tendingfrom'said channel to one end of said member, percussion explosivematerial disposed in contact .with said anvil, a readily deformablemoisture proof cup having a flange atits open end disposed around saidanvil and said material, and a centrally apertured cap in screw threadedengagement with said body to clamp the flange of said cup against saidbody.

10. A delay element for fuses, comprising a body having a first chamber,a second chamber w of less cross-sectional area than said first chamberin communication with said first chamber and a recess in the end of saidbody adjacent said second chamber but not in communication therewith; abafile member in said first chamber having a longitudinafbore of lesslength than said member, a transverse bore communicating with saidlongitudinal bore and a circumferential channel of less width than thelength of said member, and grooves extending from said channel to an endof said member; an anvil disposed at the other end of said member,percussion explosive material in contact with said anvil, a cup ofreadily deformable moisture proof material having a flange at its openend disposed around said anvil and said material, and a centrallyapertured cap in screw threaded engagement with said body to clamp theflange of said cup against said body.

11. A delay element for fuses, comprising a body, a member in said bodyprovided with a flame duct having an opening at one end of said memberand openings on the side thereof, a channel in the surface of saidmember of less width than the length of said member, passages from saidchannel to the other end of said member, an anvil seated adjacent thefirst mentioned end of said member, percussion explosive material incontact with said anvil, a deformable moisture proof cup having a flangeat its open end dis- 7 posed around said anvil and said percussionmaterial and means to clamp the flange of said cup against said body.

RAYMOND L. GRAUMANN. MAX W. FISCHER.

